use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        n: usize,
        t: u32,
        targets: [(u32, u32, u32); n],
    }

    println!("{}", output(solve(t, targets)));
}

fn solve(t: u32, mut targets: Vec<(u32, u32, u32)>) -> u64 {
    let mut dp = [0; 200_002];
    let mut pq = std::collections::BinaryHeap::with_capacity(targets.len());
    targets.sort_unstable_by_key(|&(l, _, _)| l);
    let mut targets = targets.into_iter().peekable();
    for time in 0..=200_000 {
        while let Some(&(l, r, p)) = targets.peek() {
            if l == time {
                targets.next();
                pq.push((p, r));
            }
        }
        while let Some(&(_, r)) = pq.peek() {
            if time > r {
                pq.pop();
            }
        }

        let p = pq.peek().unwrap_or(&(0, u32::MAX)).0;
        dp[(time + 1) as usize] =
            dp[time as usize].max(dp[time.saturating_sub(t - 1) as usize] + p as u64);
    }
    dp[200_001]
}

fn output(ans: u64) -> u64 {
    ans
}